An upper structure for a shoe such as shown in JP patent application publication No. 2005-329270 is proposed. The publication describes that by providing an inside expandable part on a medial side of an upper and an outside expandable part on a lateral side of the upper respectively, when a shoe wearer raises a heel and bends a foot during activities, the inside expandable part and the outside expandable part of the upper expand and contract correspondingly to deformation of the foot thus improving foot fit of the upper (see paras. [0008]-[0011], [0032]-[0034] and [0056]-[0057] and FIGS. 3 to 6 of the publication).
However, the invention described in the above publication focused only on foot movements when raising the heel to bend the foot, and never considered foot movements at all during turn motion. On the other hand, at the time of turn motion, a push-off foot moves toward a lateral side of the upper, and therefore, when the expandable part is provided at the lateral side of the upper as shown in the above publication, foot hold of the upper relative to the push-off foot decreases at the time of turn motion.